Joe Friel's Blog is for the serious endurance athlete who wants to stay current on the science and art of training for sport. Here you will find Joe Friel's thoughts and ideas before they are published anywhere else. You may also visit www.TrainingBible.com for more detailed and free content. Joe's training plans are available at www.TrainingPeaks.com.

08/17/2011

Intervals, Part 5

Let’s get back to interval training. I apologize for the long delay in posting Part 5. August has been quite busy with my annual bike tour in the Colorado mountains, selling our home in Boulder, and moving into new digs. Things are starting to settle down now, so I’m back at work.

In Part 4 I explained the terminology and commonly accepted methodology of intervals. Here’s a quick review.

Work Interval (WI). The high-intensity portions f the workout. The critical components here are WI duration and intensity. Typically, as the intensity of the WI increases its duration decreases. For sports such as running and cycling terrain is also a variable. They may be done on a flat surface or hills of varying grades. Corners may also be included, especially for cyclists preparing for criterium-style racing. Other variables are cadence (cycling), stroke (swimming), and equipment (running and cycling).

Recovery Interval (RI). The low-intensity, rest periods between the WI. Critical here are also intensity and duration. Generally as the intensity of the WI increases the intensity of the RI decreases with the reverse also being common. Long, relatively low-intensity WI are followed by short RI, as with aerobic endurance intervals explained in Part 4. In this case the ratio of WI to RI was about 4:1, meaning a long WI (20 minutes in the example) with a short RI (5 minutes in example). As you also read in the muscular force and speed skills intervals the WI duration can be quite long. A general rule is that when working on developing the cardiovascular/aerobic endurance system RI are kept short. When working on the nervous and muscular systems the RI are long. Also, over the course of several weeks of doing a particular type of interval workout it’s common for the RI to either get shorter or become slightly more intense. The reason for this is to more closely simulate the stresses of the race for which you are preparing where there are unlikely to be low-intensity, long-duration recoveries between hard efforts.

Work Interval Volume (WIV). This is the combined time of the WI within a single workout. As the intensity of the WI increases the WIV of the session decreases. The reason for this is to lower the risk of developing extreme fatigue, burnout, or injury. The sport you are training in also affects this. For example, of the three triathlon sports the one in which you are most likely to produce extreme fatigue, burnout, or injury is running. So the WIV of run intervals is usually much lower than that of swimming where the risk is considerably lower. Cycling fits between these two extremes. Your levels of fitness and experience in the sport are also critical to WIV. As these increase so does WIV.

Also in Part 4 I described the Training Triad I use in my system of training athletes. I’ve included that figure again here for reference. You may recall that in Part 4 I explained that the abilities at the corners of the Triad (aerobic endurance, muscular force, and speed skills) are the “basic” abilities. Those on the sides (muscular endurance, anaerobic endurance, and sprint power) are the “advanced” abilities. The basic abilities are most generally trained in the base period and the advanced abilities in the build period. this is not always the case. for ultra-distance events (such as Ironman, ultramarathons, etc) the advanced abilities may be developed in the late base period with aerobic endurance making up a large part of the build period.

Whenever I periodize an athlete’s season or write a weekly training plan I use this figure and these 6 abilities to help me make decisions. It’s a simple concept that I learned from Dr. Tudor Bompa.

There are other training methodologies that may work just as well for you if not better. There is not just one way to train. The key here is to keep all of the components of your personal training system cohesive and coordinated. Mixing various systems usually creates confusion and unfocused training. I frequently get questions from athletes wanting to know how they can use, for example, the heart rate zones they adopted from someone else in my workouts. I usually tell them to also use the other person’s total training system or forget the alternative zones and use mine.

Back to the topic at hand… Here are examples of interval workouts for the 6 advanced abilities.

Muscular endurance is the most basic of the advanced abilities. This is the type of workout that prepares the athlete for a steady, long race effort as when in a running race or bike time trial. For the road-racing cyclist such interval sessions pay off when riding in a fast moving peloton or steady climbing. ME training involves long work intervals (6-12 minutes) at or slightly below anaerobic threshold (or lactate threshold or functional threshold) with short RI (about 1/4th of the WI). So the work interval would be zone 4 (Coggan’s power or my heart rate zones). Depending on the sport, as explained above, an athlete should be able to do a WIV of about 20-60 minutes in a single session. This may be done once or twice a week. The workout would be something such as this:

Anaerobic endurance intervals have been shown to boost aerobic capacity (VO2max), economy, and anaerobic threshold [Billat, Laursen, Esfarjani]. This also is what often determines the outcome of a bicycle road race by preparing the rider for surges on hills, creating breaks, bridging to breaks, and racing in the wind when guttered. It is often done with work intervals that are 2-4 minutes long and done at or about aerobic capacity which is well above anaerobic threshold (Coggan’s power zone 5 or my effort or pace zone 5b). This is an intensity a well-trained athlete can only hold for about 5-6 minutes. If you can maintain the WI intensity for more than 5-6 minutes then the intensity is too low. RI are about of equal duration to the work intervals and a very low intensity, usually zone 1. I generally have athletes, depending on their sport, fitness, and experience level do 12-30 minutes of WIV of this type in a single session, once a week.

WI duration: 2-4 minutes. Runners often do these intervals on a track using a prescribed distance instead of time (for example, 800 meters). 30-second WI have also been shown to be quite effective when done with 30-second RI [Billat].

WI intensity: Any of the following: Coggan’s power zone 5 or my pace or perceived exertion zone 5b; VO2max pace or power; or CP5 or CP6 power or pace. Heart rate is not very useful for this workout as it is too slow to respond. The WI may be done on a hill to simulate race terrain.

Sprint power interval workouts are primarily used in non-steady state events in which the outcomes are determined by brief, maximal efforts. So this type of interval session falls primarily into the domain of road cyclists. Endurance runners and triathletes generally have no need for this training. One such workout is to do brief, all-out-effort sprints on varying terrain, straight-aways, and out of corners. Recovery lasts for several minutes after each sprint in order to allow subsequent intervals to be done at maximal intensity. Fatigue negates the benefits of this session. So when intensity drops by about 5% the session must end. Continuing will produce no greater benefits and may well lead to injury, deep fatigue, and burnout.

WI duration: 6-12 seconds. I often have cyclists do these intervals by counting 8-16 pedal revolutions (counting one leg only). The final, maximal portion of a finish line sprint is seldom longer than about 12 pedal revolutions.

WI intensity: Maximal effort. Heart rate is of no value in such a workout.

RI duration: 3-5 minutes.

RI intensity: A very low effort. Nearly total recovery is critical to this workout.

WIV: Stop the workout when power drops by 5%.

This ends my series on interval training. I hope you picked up something that will benefit your training. And, as always, I look forward to reading your comments.

Bill--There are 3 variables here to consider: intensity, duration and tactics. I really don't know enough about these to make a decent suggestion. Even if I was your coach it could take a long time to figure out the primary limiter.

You mentioned decoupling was a good way to measure performance when doing AE workouts, ie the athlete isn’t ready to progress to advanced ability workouts until AE is excellent. So once they are excellent you are ready to progress to the advanced workouts such as ME workouts.

So I assume you do AE workouts until decoupling is excellent then start doing ME workouts for example. Do you just keep doing those or do the gains stop after a while, such as 12 weeks is the max you could do to get any gains before you plateu, or is there another way to measure this?

Also, i assuming once build period is complete you progress to a race, but when the race season is over do you go back to AE workouts? Your fitness should be high at this stage so why go back to AE workouts?

But I have some difficulty separating the anaerobic threshold, lactate threshold or functional threshold.
I have been testet to know my AT heart rate and watt output, but I can't get a hold of AT compaired to LT and FT?

I was your coach it could take a long time to figure out the primary limiter..good blog...d I be doing Zone 4 or 5 intervals on the bike and run? And if so, how often and with what WIV per session/week...

Joe,
Excellent article on higher intensity training.
I have been trying for several weeks now to run with a more mifoot strike that will reduce braking at foot fall. I have been doing many of the Evolution Running drills yet I still seem to land with my foot ahead of my center of mass, basically digging my toe into the ground. Any suggestions on how to help plant my feet under my center of mass and reduce this braking action?
Thanks,
Barton

I've read some studies lately - I'm sure you've seen them - talking about the correlation between long-time endurance athletes and scarring of the heart due to many longer duration workout sessions. It seems clear in your books that a solid aerobic base is important, such that you recommend erring on the side of 'too much' base, and to return to base after the end of each 'season'. But, if I am worried about the above issue due to a family history of heart disease, and a personal history of higher than normal BP, would it be advantageous for me long term to avoid extended base periods and instead focus my workouts on shorter duration interval work, with maybe only 1 AE run/bike per week (ie the long run)? You, I assume, may not be able to speak to the medical side of this, but would this type of training still help me maintain an upward performance arc while not hurting longer distance races (My training is a bit hybrid, bike/swim is geared toward sprint/int from YBT, run training is a combo of faster tempo work and marathon training - 50ish miles a week) Thanks!

Thanks, Joe. That would be would be different from what I have previously done, as I always felt compelled to do some Zone 4 work to keep my "top end" sharp. But I guess there is no need to be running even a few 6:30 miles when the goal IM pace is more like 9:00.

It sounds like the Zone 3 aerobic endurance intervals desribed in Part 4 are the way to go.

But I'm a bit confused becasue in your books you refer to Zone 2 as aerobic endurance and Zone 3 as extensive endurance. Yet, the aerobic endurance intervals are actually in Zone 3. Is that right?

Barton T--run some strides on clean grass each week with your shoes off. Shoes encourage heel striking. note that I'm _not_ saying do all of your runs barefoot or even a lot of running that way. A few minutes a week at the start of a run will help you learn.

Tom--Wow, lots of questions. You can search most of these on my blog home page. As for AE measurement, note that I mentioned power-HR ratio as another way of determining when AE is well established. Until then keep doing the workout.

Nice post. It adds some detail to the info from "Your Best Triathlon", which I've been using this year.

Any thought to writing a post about brick workouts? I ran a site search and didn't see any in-depth coverage of the topic. Some people like to do longer brick workouts while others do shorter transition runs. Some don't do many bricks at all. I noticed that there was more variety with brick workouts in the Triathlete's Training Bible, while Your Best Triathlon switches the emphasis to shorter (15 min.) transition-type bricks.

I'd be interested to read whether there is specific research favoring one approach or the other. Or whether this is just one of those training topics that varies a lot according to the individual athlete. Thanks.

Perhaps a year ago at this time you wrote on the subject of VO2max intervals for older cyclists who want to retard age-related decrease in performance. Are there any conceptual differences in the design of such interval workouts - where the goal is not a specific race at a specific time? For instance, changing the work:recovery ratio or changing the duration of the work piece?
Thanks,
Madeleine

I'm trying to understand and apply some of your earlier comments on event-specificity and how training benefits of a given activity carry over to another.

What I'm missing is which of the "abilities" are specific to the muscle groups emphasized in that activity and which provide non-specific physiologic benefits.

In some cases it's clear. For example, clearly maximal force drills for cycling are of little benefit for swimming. On the other hand, aerobic training on the bike resulting in greater heart stroke volume clearly benefit all events, regardless of how you get them.

In other cases it isn't so clear. For example, when I do intervals on the bike that improve efficiency of lactic acid buffering, am I training just my legs or my entire body?

mitch--That's a great question. Of the 6 abilities I listed (aerobic endurance, muscular force, speed skills, muscular endurance, anaerobic endurance and sprint power) the only one that I would say has significant carryover to other endurance sports (e.g., in triathlon) is aerobic endurance. There is certainly some transfer of cardiorespiratory fitness (heart, lungs, blood) to other sports. But it is not 100%. In other words, an hour of aerobic endurance training in the pool is not the same as an hour of bike/run aerobic endurance as far as sport-specific benefits. One reason is that much of what we call 'cardio' training actually occurs in the working muscles. (For ex, development of aerobic enzymes.) I have never seen any studies that tried to quantify this but there are some that show a bit of a crossover.

Hi Joe,
first of all thanks for this great posts about intervals. I've also read your Training Bible and I have a question: what is the difference between the intervals for Muscular Force and Sprint interval?
They look similar to me.
Also when do you suggest to start the Muscular Force trainnig? At Base 2?
Thanks again